<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <!-- font awesome : -->
    <link rel="stylesheet" href="https://pro.fontawesome.com/releases/v5.10.0/css/all.css" integrity="sha384-AYmEC3Yw5cVb3ZcuHtOA93w35dYTsvhLPVnYs9eStHfGJvOvKxVfELGroGkvsg+p" crossorigin="anonymous"/>
    <link rel="stylesheet" href="css/bootstrap.css">
    <script src="js/bootstrap.bundle.js" async></script>
    <title>Document</title>
</head>
<body>
    <button class="btn btn-danger">Danger1</button>
    <button class="btn btn-success">Hello</button>
        
    
        <i class="fa fa-home"></i>
        <i class="fab fa-youtube fa-2x text-bg-danger"></i>
        <i class="fab fa-facebook"></i>
        <i class="fab fa-facebook fa-2x text-bg-primary"></i>


</body>
</html>